A buffer overflow can occur in the Skia library during buffer offset calculations with hardware accelerated canvas 2D actions due to the use of 32-bit calculations instead of 64-bit. This results in a potentially exploitable crash.

A use-after-free vulnerability can occur after deleting a selection element due to a weak reference to the select element in the options collection. This results in a potentially exploitable crash.

Mozilla developers and community members Christian Holler, Diego Calleja, Andrew McCreight, Jon Coppeard, Jed Davis, Natalia Csoregi, Nicolas B. Pierron, and Tyson Smith reported memory safety bugs present in Firefox 63 and Firefox ESR 60.3. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code.

A WebExtension can request access to local files without the warning prompt stating that the extension will "Access your data for all websites" being displayed to the user. This allows extensions to run content scripts in local pages without permission warnings when a local file is opened.

A vulnerability where a WebExtension can run content scripts in disallowed contexts following navigation or other events. This allows for potential privilege escalation by the WebExtension on sites where content scripts should not be run.

By rewriting the Host request headers using the webRequest API, a WebExtension can bypass domain restrictions through domain fronting. This would allow access to domains that share a host that are otherwise restricted.

When manipulating user events in nested loops while opening a document through script, it is possible to trigger a potentially exploitable crash due to poor event handling.

During HTTP Live Stream playback on Firefox for Android, audio data can be accessed across origins in violation of security policies. Because the problem is in the underlying Android service, this issue is addressed by treating all HLS streams as cross-origin and opaque to access. Note: this issue only affects Firefox for Android. Desktop versions of Firefox are unaffected.

Mozilla developers and community members Christian Holler, Bob Owen, Boris Zbarsky, Calixte Denizet, Jason Kratzer, Jed Davis, Taegeon Lee, Philipp, Ronald Crane, Raul Gurzau, Gary Kwong, Tyson Smith, Raymond Forbes, and Bogdan Tara reported memory safety bugs present in Firefox 62 and Firefox ESR 60.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code.

A vulnerability where the JavaScript JIT compiler inlines Array.prototype.push with multiple arguments that results in the stack pointer being off by 8 bytes after a bailout. This leaks a memory address to the calling function which can be used as part of an exploit inside the sandboxed content process.